1. Field
Example embodiments relate to high electron mobility transistors (HEMTs) and methods of manufacturing the same, and more particularly to HEMTs including oxygen treated regions and methods of manufacturing the same.
2. Description of the Related Art
A high electron mobility transistor (HEMT) includes semiconductors with different band gaps. In a HEMT, semiconductors with different band gaps are joined together. A semiconductor with a relatively wide band gap functions as a donor. Such a semiconductor with the relatively wide band gap forms a 2-dimensional electron gas (2DEG) in a semiconductor with a relatively narrow band gap. In a HEMT, the 2DEG may be used as a channel.
A HEMT may be a transistor with improved charge carrier mobility and a high breakdown voltage, and may act as a power device. The relatively wide band gap semiconductor may be a compound semiconductor. Therefore, a breakdown voltage of a HEMT may be high. A 2DEG may be formed by n-doping a material having a relatively wide band gap or by using a polarized material. Because a HEMT includes a channel without application of an external electric field, the HEMT operates in a depletion mode.
However, in order to simplify a circuit, a HEMT may operate in an enhancement mode (hereinafter, referred to as an ‘E-mode’). The E-mode may be realized by removing a channel disposed below a gate. In a HEMT, the 2DEG between a gate and a drain is removed during a turning-off operation. A space charge remains and an electric field is concentrated at the gate due to the space charge. Due to the concentration of the electric field at the gate, the breakdown voltage of the HEMT may decrease.
In order to realize an E-mode and/or increase a breakdown voltage of a HEMT, the polarizability of a channel supplying layer may be reduced by etching a portion of the channel supplying layer using chlorine (Cl) based gases, or fluorine (F) based gases may be put into the channel layer to function as an acceptor. However, because both Cl and F produce corrosive gases the HEMT may be damaged during the etching of the channel supplying layer.